Prior art developments in the field of underwater installation of objects found in the offshore oil and gas industries have primarily relied on guide wires extending from the installation site to the water surface in order to accurately position the object on the installation site.
In deepwater, in depths of several hundreds or even thousands of meters, guide wires are no longer practical. In U.S. Pat. No. 6,588,985, a load carrying ROV has been proposed to lower large heavy objects and position them at an underwater installation site without the use of guide wires.
It is also known for deepwater installation to use a deepwater crane and position the object onto the installation site using a free-swimming ROV.